Spectral Characterization of Dissolved Organic Matter in Seawater and Sediment Pore Water from the Arctic Fjords (West Svalbard) in Summer
Fjords in the high Arctic, as aquatic critical zones at the interface of land-ocean continuum, are undergoing rapid changes due to glacier retreat and climate warming. Yet, little is known about the biogeochemical processes in the Arctic fjords. We measured the nutrients and the optical properties o...
Published in: | Water |
---|---|
Main Authors: | , , , , , , |
Format: | Text |
Language: | English |
Published: |
Multidisciplinary Digital Publishing Institute
2021
|
Subjects: | |
Online Access: | https://doi.org/10.3390/w13020202 |
id |
ftmdpi:oai:mdpi.com:/2073-4441/13/2/202/ |
---|---|
record_format |
openpolar |
spelling |
ftmdpi:oai:mdpi.com:/2073-4441/13/2/202/ 2023-08-20T04:03:34+02:00 Spectral Characterization of Dissolved Organic Matter in Seawater and Sediment Pore Water from the Arctic Fjords (West Svalbard) in Summer Meilian Chen Ji-Hoon Kim Sungwook Hong Yun Kyung Lee Moo Hee Kang Young Keun Jin Jin Hur agris 2021-01-15 application/pdf https://doi.org/10.3390/w13020202 EN eng Multidisciplinary Digital Publishing Institute Oceans and Coastal Zones https://dx.doi.org/10.3390/w13020202 https://creativecommons.org/licenses/by/4.0/ Water; Volume 13; Issue 2; Pages: 202 dissolved organic matter excitation emission matrix glaciofluvial runoff ice algal bloom Arctic glaciomarine sediment Text 2021 ftmdpi https://doi.org/10.3390/w13020202 2023-08-01T00:52:33Z Fjords in the high Arctic, as aquatic critical zones at the interface of land-ocean continuum, are undergoing rapid changes due to glacier retreat and climate warming. Yet, little is known about the biogeochemical processes in the Arctic fjords. We measured the nutrients and the optical properties of dissolved organic matter (DOM) in both seawater and sediment pore water, along with the remote sensing data of the ocean surface, from three West Svalbard fjords. A cross-fjord comparison of fluorescence fingerprints together with downcore trends of salinity, Cl−, and PO43− revealed higher impact of terrestrial inputs (fluorescence index: ~1.2–1.5 in seawaters) and glaciofluvial runoffs (salinity: ~31.4 ± 2.4 psu in pore waters) to the southern fjord of Hornsund as compared to the northern fjords of Isfjorden and Van Mijenfjorden, tallying with heavier annual runoff to the southern fjord of Hornsund. Extremely high levels of protein-like fluorescence (up to ~4.5 RU) were observed at the partially sea ice-covered fjords in summer, in line with near-ubiquity ice-edge blooms observed in the Arctic. The results reflect an ongoing or post-phytoplankton bloom, which is also supported by the higher levels of chlorophyll a fluorescence at the ocean surface, the very high apparent oxygen utilization through the water column, and the nutrient drawdown at the ocean surface. Meanwhile, a characteristic elongated fluorescence fingerprint was observed in the fjords, presumably produced by ice-edge blooms in the Arctic ecosystems. Furthermore, alkalinity and the humic-like peaks showed a general downcore accumulation trend, which implies the production of humic-like DOM via a biological pathway also in the glaciomarine sediments from the Arctic fjords. Text Arctic glacier Hornsund Isfjord* Isfjorden Phytoplankton Sea ice Svalbard Van Mijenfjorden MDPI Open Access Publishing Arctic Svalbard Hornsund ENVELOPE(15.865,15.865,76.979,76.979) Van Mijenfjorden ENVELOPE(14.667,14.667,77.717,77.717) Water 13 2 202 |
institution |
Open Polar |
collection |
MDPI Open Access Publishing |
op_collection_id |
ftmdpi |
language |
English |
topic |
dissolved organic matter excitation emission matrix glaciofluvial runoff ice algal bloom Arctic glaciomarine sediment |
spellingShingle |
dissolved organic matter excitation emission matrix glaciofluvial runoff ice algal bloom Arctic glaciomarine sediment Meilian Chen Ji-Hoon Kim Sungwook Hong Yun Kyung Lee Moo Hee Kang Young Keun Jin Jin Hur Spectral Characterization of Dissolved Organic Matter in Seawater and Sediment Pore Water from the Arctic Fjords (West Svalbard) in Summer |
topic_facet |
dissolved organic matter excitation emission matrix glaciofluvial runoff ice algal bloom Arctic glaciomarine sediment |
description |
Fjords in the high Arctic, as aquatic critical zones at the interface of land-ocean continuum, are undergoing rapid changes due to glacier retreat and climate warming. Yet, little is known about the biogeochemical processes in the Arctic fjords. We measured the nutrients and the optical properties of dissolved organic matter (DOM) in both seawater and sediment pore water, along with the remote sensing data of the ocean surface, from three West Svalbard fjords. A cross-fjord comparison of fluorescence fingerprints together with downcore trends of salinity, Cl−, and PO43− revealed higher impact of terrestrial inputs (fluorescence index: ~1.2–1.5 in seawaters) and glaciofluvial runoffs (salinity: ~31.4 ± 2.4 psu in pore waters) to the southern fjord of Hornsund as compared to the northern fjords of Isfjorden and Van Mijenfjorden, tallying with heavier annual runoff to the southern fjord of Hornsund. Extremely high levels of protein-like fluorescence (up to ~4.5 RU) were observed at the partially sea ice-covered fjords in summer, in line with near-ubiquity ice-edge blooms observed in the Arctic. The results reflect an ongoing or post-phytoplankton bloom, which is also supported by the higher levels of chlorophyll a fluorescence at the ocean surface, the very high apparent oxygen utilization through the water column, and the nutrient drawdown at the ocean surface. Meanwhile, a characteristic elongated fluorescence fingerprint was observed in the fjords, presumably produced by ice-edge blooms in the Arctic ecosystems. Furthermore, alkalinity and the humic-like peaks showed a general downcore accumulation trend, which implies the production of humic-like DOM via a biological pathway also in the glaciomarine sediments from the Arctic fjords. |
format |
Text |
author |
Meilian Chen Ji-Hoon Kim Sungwook Hong Yun Kyung Lee Moo Hee Kang Young Keun Jin Jin Hur |
author_facet |
Meilian Chen Ji-Hoon Kim Sungwook Hong Yun Kyung Lee Moo Hee Kang Young Keun Jin Jin Hur |
author_sort |
Meilian Chen |
title |
Spectral Characterization of Dissolved Organic Matter in Seawater and Sediment Pore Water from the Arctic Fjords (West Svalbard) in Summer |
title_short |
Spectral Characterization of Dissolved Organic Matter in Seawater and Sediment Pore Water from the Arctic Fjords (West Svalbard) in Summer |
title_full |
Spectral Characterization of Dissolved Organic Matter in Seawater and Sediment Pore Water from the Arctic Fjords (West Svalbard) in Summer |
title_fullStr |
Spectral Characterization of Dissolved Organic Matter in Seawater and Sediment Pore Water from the Arctic Fjords (West Svalbard) in Summer |
title_full_unstemmed |
Spectral Characterization of Dissolved Organic Matter in Seawater and Sediment Pore Water from the Arctic Fjords (West Svalbard) in Summer |
title_sort |
spectral characterization of dissolved organic matter in seawater and sediment pore water from the arctic fjords (west svalbard) in summer |
publisher |
Multidisciplinary Digital Publishing Institute |
publishDate |
2021 |
url |
https://doi.org/10.3390/w13020202 |
op_coverage |
agris |
long_lat |
ENVELOPE(15.865,15.865,76.979,76.979) ENVELOPE(14.667,14.667,77.717,77.717) |
geographic |
Arctic Svalbard Hornsund Van Mijenfjorden |
geographic_facet |
Arctic Svalbard Hornsund Van Mijenfjorden |
genre |
Arctic glacier Hornsund Isfjord* Isfjorden Phytoplankton Sea ice Svalbard Van Mijenfjorden |
genre_facet |
Arctic glacier Hornsund Isfjord* Isfjorden Phytoplankton Sea ice Svalbard Van Mijenfjorden |
op_source |
Water; Volume 13; Issue 2; Pages: 202 |
op_relation |
Oceans and Coastal Zones https://dx.doi.org/10.3390/w13020202 |
op_rights |
https://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.3390/w13020202 |
container_title |
Water |
container_volume |
13 |
container_issue |
2 |
container_start_page |
202 |
_version_ |
1774713977190744064 |